Electric switch



1929- Y H, J. HAMMERLY 1,740,858

- ELECTRIC SWITCH Fi led Jan. 29, 1929 2 Sheets-Sheet 1 1241 1 4 0 L I 1.9m 1 Z6 ji HI Z1 fill;

Dec. 24, 1929.

H. J. HAMMERLY v ELECTRIC SWITCH 2 Sheets-Sheet 2 I Filed Jan. 29, 1929 eff.

INVENTOR work loose or become broken.

Patented Dec. 24, 1929 UNITED STATES PATENT OFFICE 4 HERMAN J. HAMMERLY, OF WALLINGFORD, CONNECTICUT, ASSIGNOR TO THE TRUM- BULL ELECTRIC MANUFACTURING COMPANY, OF PLAINVILLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT ELECTRIC SWITCH Application filed January 29, 1929. Serial No. 835,891:

My invention relates particularly to quickmake and -break switches. The main object is to provide a. simple but reliable and durable shock absorbing and connector means which is particularly applicable to switches of the slate base type. Such mechanisms are subjected to severe shock in the closing move ment and the parts consequently frequently One of my objects accordingly is to so construct and arrange the parts as to cushion the impact and thus minimize the danger of fracture or loosening of the parts. Another object is to provide a construction of a character which will prevent or minimize arcing between the movable blade and the stationary jaw post in the opening movement of the switch.

In the accompanying drawings I have illustrated a desirable form of mechanism involving my invention. The preferred form of quick-make and -break mechanism is more fully shown, described and claimed in my application No. 280,088 filed May 23, 1928. The switch base will usually be formed of slate and may, as illustrated, be mounted in any suitable form of box. The contacts, terminals, and circuit protecting fuses may be of any suitable character. The switch proper may include any number of movable blade units as for instance 2, as shown herein. Each unit is mounted on the insulating base and has a blade hinged in the usual manner and adapted to engage a suitable jaw or contact member. An operating crank and a quick break mechanism are mounted in a suitable enclosing box and provided with an external operating handle. v I

The connection between the crank and each switch blade is eifected by an insulating bar or plate, preferably of fibre or the like, having a slotted connection with the crank and being riveted to the blade. This plate extends beyond the blade and serves as a shock absorbing abutment to the blade at the end of the circuit closing movement and also as astop for limiting the throw of the blade. This plate is so located as to pass close to the contact jaw in the circuit opening moveswitch involving my invention, the cover being shown open and partly broken away and the switch being.in a closed circuit position.

Figs. 2, 3 and 3 are perspective views of switch blades and their attached insulating connectors, which serve as shock absorbers and are interrupters showing three modifications.

Fig. 4 is a vertical section and side elevation of one of the switch units in a closed circuit position. A

.Fig. 5 is a similar view in a circuit opening position.

Fig. 6 is an edge View of one of the switch units in a circuit opening position showing a modified form of connector.

Fig. 7 is a similar view of another modified form of connector.

The box 10 in the form shown has a hinged cover 11. These may be of any suitable form and provided with catches, etc. as is common in the art.

The switch base 12 is usually of slate or other suitable insulating material and suitably connected to the bottom of the box.

Each switch unit has circuit terminals 13 and 14 and clips 15 and 16 for the fuse 17. The stationary contacts of the switch unit are in the form of a post 18 and the spring jaws 19. In the particular form shown the movable switch member 20 has an end hinged to the post 18 and the other end adapted to engage the jaws 19. Each movable switch member or blade 20 is provided with a connector plate 21 preferably formed of fibre riveted at 22 to the blade.

Any number of these switch blade units did the preferred method of supporting the movable parts. It is sulhcient to note that for the purpose of this application .I prefer to utilize a bushing 24 which is rotatably mounted on one wall of the box and serves as'a bearing for one end of the crank 23. The throwing disc is rotatably mounted on this bushing and is suitably connected to the throwing spring 26 which has a stationary abutment 27. The handle 28 is mounted on the outer end of the bushing 2t and has a suitable lost-motion connection through the wall of the box with the disc 25, which in turn has a lost-motion connection with the crank 23. The quick break mechanism, as its name implies, opens the switch with a snap action and closes the switch with a snap action. The shock of the opening movement is taken up by the stationary bracket 29 secured to the inside of the box. The shock of the closing movement is taken up by the impact of the lower ends 30 ot the various connectors above described. These connectors being of more or less yielding or resilient material, serve as non-metallic shock absorbers which distribute the impact or stress without tending to crack or chip the base. \Vhen the circuit is opened the corner of the insulating plate snaps past the edge of contact jaw 19 and thus tends to cut off or obstruct any are which may tend to form. It will thus be seen that the insulating plate 21 serves the quadruple purpose of a convenient connector between the crank 23 and the switch blade 20, an arc interrupter, and as a stop for blades in the closing movement and a shock absorber.-

In the form shown in Fig. 6 the lower end of the connector 21 is broadened out at 31 beneath the blade sons to provide a wider foot for distributing the shock of the circuit Closing movement and for interrupting any are which tends to form.

In the form shown in Figs. 8 and 7 there are two plates 21 and21 on opposite sides of the blade 20 with an intervening insulating layer 32 between their lower ends beneaththe blade. This gives additional reinforcement to the shock absorbing feature and also provides additional are interrupting material at the most effective position.

In the form shown in Fig. 3 two insulattions, for instance, in ordinary hand operated knife switches.

It should be understood that other changes in construction and arrangement may be made without departing from the spirit or scope of my invention.

I claim:

1. In an electric switch, an ansulating base a switch unit carried thereby, said unit in-' 2. In an electric switch, a base, a plurality of switch units carried thereby, each unit including a hinged blade and a stationary jaw to receive the movable end ot the blade, an operating crank for said blade and a fibre plate secured to each switch blade and connectible to said crank independently of the other blades, each plate having an extension for abutting against the base in the circuit closing movement and serving as an arc interrupter in the circuit opening movement of the switch.

3. In an electric switch, an insulating base, a switch unit carried thereby, consisting of a supporting post, a blade hinged to said post and a stationary jaw to receive the movable end of the blade, an operating crank for said blade and a resilient plate secured to said switch blade said plate having a slotted connectiori with said crank and having a foot for abutting against the base in the circuit closing movement and said foot serving as an arc interrupter in the circuit opening movement of the switch.

4. In an electric switch, a base, a plurality of switch units carried thereby, each unit consisting of a supporting post, a blade hinged to said post and a stationary jaw to receive the movable end. of the blade, an operating crank for said blade and an insulating plate secured to each blade and connectible to said crank independently of the other blades, each plate having a foot for abutting against the base in the circuit closing move- .ment and said foot serving as an arc interrupter in the circuit opening movement of the switch.

HERMAN J. HAMMERLY. 

